Compilare: main.cpp: In function 'int main()': main.cpp:62:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sol.size()==n){ ~~~~~~~~~~^~~ main.cpp:18:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("domino.in","r",stdin); ^ main.cpp:19:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("domino.out","w",stdout); ^ main.cpp:21:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:23:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("\n%d %d", &x, &y); ^